Anatomy of the Head: Compartments and Cavities

Head and Neck Overview

• The head and neck are anatomically complex areas of the body
• The face is the anterior aspect of the head and contains a unique group of muscles
• The scalp covers the superior, posterior, and lateral regions of the head

Neck

• The neck extends from the head above to the shoulders and thorax below
• Its superior boundary is along the inferior margins of the mandible and bone features on the posterior aspect of the skull
• The inferior boundary of the neck extends from the top of the sternum, along the clavicle, and onto the adjacent acromion
• The posterior neck is higher than the anterior neck to connect cervical viscera with the posterior openings of the nasal and oral cavities

Neck Compartments

• The neck has four major compartments, which are enclosed by an outer musculofascial collar
• The vertebral compartment contains the cervical vertebrae and associated postural muscles
• The visceral compartment contains important glands (thyroid, parathyroid, and thymus), and parts of the respiratory and digestive tracts
• The two vascular compartments, one on each side, contain the major blood vessels and the vagus nerve

Larynx and Pharynx

• The neck contains two specialized structures associated with the digestive and respiratory tracts—the larynx and pharynx
• The larynx is the upper part of the lower airway and is attached below to the top of the trachea and above to the hyoid bone
• The larynx has a hollow central channel, and the dimensions of this central channel can be adjusted by soft tissue structures associated with the laryngeal wall
• The pharynx is a chamber in the shape of a half-cylinder with walls formed by muscles and fascia

Head Compartments

• The head is composed of a series of compartments, which are formed by bone and soft tissues
• The cranial cavity, two ears, two orbits, two nasal cavities, and an oral cavity are the main compartments of the head
• The nasal cavities are the upper parts of the respiratory tract and are between the orbits
• The oral cavity is inferior to the nasal cavities, and separated from them by the hard and soft palates

Explore the complex anatomy of the head and neck, including the different compartments and cavities. Learn about the cranial cavity, ears, orbits, nasal cavities, and oral cavity. Understand the structure and composition of these areas.